LinnaeusLeichhardt treebranchesfirst named this tree as Cephalanthus orientalis in the first edition of Species Plantarum in 1753, but changed the genus to Nauclea in the second edition in 1763. There is some doubt as to the derivation of the generic, but although most authorities seem to agree that it is based on the Greek ναυς (naus), a ship, none seem to agree on why Linnaeus might have used it. Orientalis is Latin for ‘of the east’, and the common name Leichhardt refers to the explorer Ludwig Leichhardt, who encountered the tree on his first expedition from Moreton Bay to Port Essington (1844 -1845), although he mis-identified it.

The native range of the species extends from northern Australia and New Guinea to South-East Asia, including Sri Lanka. In Queensland it extends down most of the east coast, to about Gladstone. It is a characteristic tree of the gallery forests in northern Australia, but is also found in riparian and lowland forest, and in melaleuca swamps. Adult trees are flood tolerant, and moderately tolerant of occasional fires. These are medium to tall trees, up to about 30 m tall, and are deciduous, shedding their leaves in the dry season. They are roughly pyramidical in shape, with distinctive horizontal branches. The bark surface is greyish to reddish brown, and may be smooth, but is often fissured or flaky, and becomes corky with age. Dead bark is orange to yellow when cut. The leaves are quite large, simple, opposite, ovate in shape, about 7 – 30 cm long by 4 – 18 cm wide. The upper surface is a glossy green, while the lower surface is lighter, and shows the prominent yellow veins. New growth is protected by large oval stipules, up to about 4 cm long. On their inside surfaces there are a number of small red glands that look a bit like insect eggs.

trunkleavesSmall tubular fragrant flowers, yellow and white in colour, occur in dense globular heads about 3 – 5 cm in diameter. The individual flowers are less than 1 cm long. There is a perianth, consisting of 5 petals and sepals in separate whorls. The flowers are bisexual, with 5 or 6 short and separate stamens attached to the perianth.

After about 3 months, the flower heads develop into a fleshy globular syncarp joined by their calyces, each flower becoming a fruitlet containing one tiny seed, about 1.5 by 1 mm. The fruit is reticulately wrinkled, brown, and strongly aromatic, very popular with fruit bats and cassowaries. They are also eaten by indigenous Australians, although they are very bitter in taste. In Malaysia they are eaten by proboscis monkeys.

The wood is easily cut, but is not durable when in contact with the ground. It is yellow to orange in colour, and is used for frames and interior floorboards. It is suitable for wood turning and carving. The bark is used to make a fish poison, which is added to slow-moving bodies of water to stun the fish and make them easier to catch. The large leaves can be used as plates. The trunks are easily hollowed out, and are used to make canoes and coolamons.

Infusions of the bark are used in folk medicine. In the Philippines it is used to treat wounds, and among indigenous Australians to treat stomach aches (it induces vomiting) and also animal bites, including those of snakes.

Huge hawk moth larvae can strip the trees of their leaves, but they rapidly recover.